Water Reuse = Energy Efficiency

One California water utility plans to be off the grid by 2020.

The IEUA joined the RAND Corp. with funding from the National Science Foundation to conduct a study of the potential impacts of climate change on the water supplies of the IEUA service area. The modeling analysis identified the potential vulnerabilities and risks to the Colorado River and northern California water supplies as a result of climate change, such as reduced snowpack, longer and more extreme droughts, and increased peak storm runoff requiring additional storage. Photos: Inland Empire Utilities Agency

The environment has taken center stage in the Obama administration, but a California-based municipal water and wastewater utility, which operates five water-recycling facilities for 880,000 residents 35 miles east of Los Angeles, already has spent the last five years embarking on a comprehensive strategy to reduce its energy use and to generate the majority of its electrical needs through renewable biogas, energy generated onsite, and solar power.

The Inland Empire Utilities Agency (IEUA), located in San Bernardino County, was formed as a wholesale water utility in 1950 to become a member agency of the Metropolitan Water District (MWD) of Southern California to receive imported water from the Colorado River. IEUA has grown to a regional wholesale water and wastewater utility with a current electrical consumption of about 12 MW annually.

About one-third of the water distributed by the IEUA is imported from the MWD via the California State Water Project (SWP) and from the Colorado River from MWD's aqueduct built in the 1930s. The remaining two-thirds is derived from local ground-water and surface runoff.

But importing water to southern California is very energy-intensive: The SWP uses about six times the energy, and the Colorado River uses about four times the energy of a local groundwater well in Ontario, Calif., to supply the IEUA service area.

The SWP does not pay the entire bill, though. Charges are billed to the MWD, which in turn bills the IEUA its prorate share based on water delivery.

Overall, energy use by water and waste-water utilities in California is a significant issue: About 19% of all electrical consumption in the state is related to pumping, treating, and distributing water. Energy use will only increase with population growth. The service area of the IEUA is expected to grow by an estimated 50% over the next 20 years to about 1.3 million people.

Given the growth trends, the agency's five-member, elected board of directors and management team recognized the need to develop new local water supplies to offset the need for additional imported water, to reduce the potential for drought in its 242-square-mile service area, and to reduce its net energy use.

In addition, climate change likely will affect water supplies in California and the arid Southwestern portions of the United States in the next decade as reported by the U.S. Bureau of Reclamation.

As result of a feasibility study commissioned by a National Science Foundation grant of $1.5 million and conducted by the RAND Corp., the IEUA decided to increase investments in local supplies by adopting a multifaceted strategy that would capitalize on increased conservation, recycled water, and stormwater capture in the local groundwater aquifers. Specifically, the IEUA decided to accelerate water conservation practices; expand a water distribution system for irrigation and industrial uses by replacing drinking water with recycled water; and utilize local groundwater supplies as effectively as possible.

The strategy was designed to increase water supply reliability while reducing the utility's dependence on imported water.